Nicky Cavella was the son of a respected Mafia member.
When he was eight years old, Nicky's Aunt Mo ordered him to kill his parents and his younger sister to frame Uncle Jimmy for the killings and take over his father's operation. Mo raised him to learn how to operate in the Mafia and when he began his adulthood she forced him to have sex with her. After a few years of enduring this physical abuse, Cavella choked his aunt to death with a pillow.
Eventually, he worked for Don Cesare and was ordered to scare rival crime lord David Kai as a trial to join the Mafia. At the meeting, Cavella murdered David Kai's children, but left Kai alive. Due to Cavella's brutality, the Mafia exiled him to Boston, along with his crew of killers, Pittsy and Ink. In Boston, Cavella started having relations with corrupt military officer William Rawlins.
After the Punisher crippled the Massimo crime family, Nicky Cavella was summoned to assassinate the Punisher. Nicky agreed but first they had to eliminate the Punisher, who at that time was being interrogated by Microchip who was operating with the CIA to force Frank Castle to work with the Government in counter-terrorism. Pittsy castrated agent William Roth to tell him where they held Castle. He was kept in a hotel. They went in and wounded and killed other agents including Micro. Pittsy was shot in his shoulder and Ink was killed by Kathryn O'Brien. Micro and Frank escaped to one of the Punisher's safehouses and Cavella sent an army of Mafiosos to kill them but they failed. Pittsy went to kill him but was impaled on a gate. So Cavella forced Barrucci to fight the Punisher but Larry was instantly shot in the thorax. Frank was following Nicky but was interrupted by a dying Pittsy. Pittsy was shot in the face. Later Cavella killed two cops and ran away in their car.
After two years he became known as one of the few criminals to survive at meeting with the Punisher. He became more dangerous when he and Teresa Gazzera, Pittsy's sister, profaned the Castle family grave and urinated on the bodies, this permitted him to be elected as the Don. Cavella obviously thought that Punisher will run after him but instead he massacred local gangs. His former lover Bill Rawlins was ordered by CIA to stop Frank Castle, so he teamed up with Cavella to make a perfect plan. The plan was that Rawlins would shoot Castle with a sniper while he's attacking Cavella who will be sitting on a chair as a bait. The plan fails because Rawlins' ex-wife, Kathryn O'Brien alongside Will Roth kidnap Rawlins and she starts to shoot at Cavella's men and saving Castle and taking him with them. Cavella and Teresa follow their car at Roth's apartment were Rawlins is brutally interrogated. Teresa tries to seduce Nicky but he pushed her away, in order to like her she goes in but is killed by Castle and O'Brien who were having sex. Rawlins kills Roth and escapes. The next day as Castle and O'Brien get out, they face Cavella who is holding a boy hostage. Castle warns him that if he hurts the boy he'll give him a hellish death, as soon as he hears this his cowardliness comes out and leaves the boy. He's put in the luggage booth and taken to a far away forest were Frank shoots him in the belly while explaining him how he'll die. After three days he died a slow and painful death, probably because of blood poisoning. Hunters found him with his eyes pecked out by birds.